Solutions are known in the art permitting wavelength conversion and regeneration of optical signals by using interferometers.
For instance, Mach Zehnder Interferometer All Optical Wavelength Converters (MZI-AOWC) are known based on a counter-propagating configuration. Also, Michelson Interferometer All Optical Wavelength Converters (MI-AOWC) are known. These are generally simpler than MZI-AOWC whose counter-propagating configuration is also responsible for appreciable limitations in terms of bandwidth in comparison with solutions based on the use of Michelson Interferometers (MI).
For instance, from L. Zucchelli et al., “System assessment of a compact monolithic Michelson interferometer wavelength converter”, European Conference on Integrated Optics, ECIO'99, 14–16, Apr. 1999—Turin (Italy), pp. 479–482 a Michelson interferometer is known including passive optical waveguides forming a 50:50 optical coupler monolithically integrated with two Semiconductor Optical Amplifiers (SOA's). Specifically, wavelength conversion and 2R (Reshaping-Reamplification) regeneration is disclosed in connection with incoming data which are directly fed to one of the two SOA's, while the local signal enters the device from one of the passive waveguides. If the input signal (whose wavelength is not known a priori) happens to have the same wavelength desired at the output, conversion is not possible since the local signal and the incoming data cannot be separated.
Use of a substantially similar device as a data regenerator is also demonstrated in D. Wolfson et al., “All-optical 2R regeneration based on interferometric structure incorporating semiconductor optical amplifiers”, Electronics Letters, 7, Jan. 1999, vol. 35, no. 1. There, the two SOA's are polarised at two different working points, the data enter the device through passive ports and, thanks to the non-linear characteristic of the device, regeneration is effected without however making it possible to obtain wavelength conversion.